static Tuple <EntryPartition, EntryPartition> GetRangeForLowerReversedDateBoundBinarySearch(
IAzureDiagnosticLogsTable wadTable,
long dateTicks,
EntryPartition searchRangeBegin,
CancellationToken cancellationToken)
{
EntryPartition datePartition = new EntryPartition(new EntryTimestamp(dateTicks));
EntryPartition lastStepPartition = datePartition;
for (int step = 1; ; step *= 2)
{
EntryPartition p = EntryPartition.Max(searchRangeBegin, datePartition.Advance(step));
if (EntryPartition.Compare(p, lastStepPartition) == 0)
{
return(null);
}
var tmp = wadTable.GetFirstEntryOlderThan(p.ToString());
if (tmp != null && tmp.EventTickCount < dateTicks)
{
return(new Tuple <EntryPartition, EntryPartition>(
new EntryPartition(tmp.PartitionKey),
lastStepPartition.Advance()));
}
lastStepPartition = p;
cancellationToken.ThrowIfCancellationRequested();
}
}
static Tuple <EntryPartition, EntryPartition> GetRangeForLastMessageBinarySearch(IAzureDiagnosticLogsTable wadTable, DateTime utcNow, CancellationToken cancellation)
{
EntryPartition initialPartition = new EntryTimestamp(utcNow).Partition;
bool thereAreEntriesOlderThanNow = wadTable.GetFirstEntryOlderThan(initialPartition.ToString()) != null;
bool searchingForward = thereAreEntriesOlderThanNow;
EntryPartition currentPartition = initialPartition;
for (long step = searchingForward ? 1 : -1; ; step *= 2)
{
cancellation.ThrowIfCancellationRequested();
EntryPartition t = initialPartition.Advance(step);
if (EntryPartition.Compare(currentPartition, t) == 0)
{
return(null);
}
var tmp = wadTable.GetFirstEntryOlderThan(t.ToString());
if (searchingForward)
{
if (tmp == null)
{
return(new Tuple <EntryPartition, EntryPartition>(currentPartition.Advance(), t));
}
}
else
{
if (tmp != null)
{
return(new Tuple <EntryPartition, EntryPartition>(new EntryPartition(tmp.EventTickCount), currentPartition.Advance()));
}
}
currentPartition = t;
}
}